It is known that the onset of acne is generally caused by the following four reasons: 1) excessive production of sebum; 2) excessive cell division of follicular epithelium and thus blocking of pores; 3) production of inflammation due to proliferation of Pro-pionibacterium acne (P.acne) and generation of prefatty acid; and 4) inflammation of follicle and its surrounding area. A major factor affecting the pathogeny mechanism comprises climate or weather, season, modification of gene or hormone, skin wastes, and others.
The onset causes of the acne will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view schematically illustrating the surrounding area of a pore, and FIG. 2 is a cross-sectional view schematically illustrating inflammatory acne developed around the pore.
Referring to FIGS. 1 and 2, if a sebum 4 is excessively secreted from a sebum gland 2, the sebum 4 is not smoothly discharged from the sebum gland 2, and thus is accumulated in a pore 8. The prefatty acid generated by Propionibacterium acne which is proliferated in the pore 8 stimulates the skin around the pore, which can cause inflammation in the wall of a hair follicle and an area around the pore.
With the inflammation, a stratum corneum S1 is abnormally proliferated around the pore 8, and edema caused by the inflammation 10 blocks the pore 8 to further obstruct the smooth discharge of the sebum. Hence, symptoms of acne are developed on the skin. In the drawings, reference numeral S2 denotes an epidermal layer, S3 denotes a dermal layer, and 9 denotes a hair root.
The acne treatment generally takes aim at one or some of four pathogeny mechanisms as described above.
The acne developed by the above reasons is generally cured by the following conventional methods:
1) a method of dosing a patient with drugs such as antibiotics, retinoids, or steroid;
2) a method of using an external application; and
3) a surgical method such as comedo extraction, chemical peeling, or the like.
However, the conventional methods have a limited effect, and give rise to several side effects.
In particular, in case of the chemical peeling in which a chemical drug is applied onto the epidermis to peel off the epidermal layer, the clogged pores are opened to allow the sebum to be smoothly discharged, and the inflamed tissues are eliminated from the skin. However, experienced operators are required, and it is not possible to precisely control a penetrated depth when the drugs are applied, thereby possibly giving rise to side effects, for example, scar or hyper-pigmentation caused by excessive peeling of the epidermal layer. Although a laser having a wavelength of about 400 nm or intense pulsed light is used to cure the acne, because it cannot open the clogged pores, a desired curing effect is not expected. Any method cannot effectively treat the acne to date.